The present invention relates to a system comprising a micro-controller, an interface controller and an IC card as a portable data medium, and a respective device communicating with the portable data medium. Systems of this kind are used for example for Pay TV, electronic payment, or banking services.
For these applications compact portable data media are used, having the size of about a credit card, and which comprise an integrated card-controller, or at least an integrated memory, for data exchange with a respective device. Data media of this kind are known for example as smart card, IC card or identification card, and described for example in EP-A-0 633 544. As a general term for these data media, the expression “IC card” will be used in this description.
Systems as described above are known for example from WO 98/00772 and WO 97/25685. A standard with a specification for a special type of IC cards is defined in ISO/IEC 7816-3:1997(E). In this standard the design and the operation procedures for integrated circuit cards with contacts (identification cards) are described.
As an interface controller for providing the data exchange between the microcontroller of a respective device and an IC card, integrated circuits are known, for example TDA 8004T from Philips Semiconductors, which are coupled between the microcontroller and the IC card. The interface controller provides also the voltage supply and the control functions with automatic activation and deactivation sequences for the IC card.
The object of the invention is to provide a system with an IC card as described above, which gives a user an improved safety of operation.